American agricultural commodities in a changing climate

Although climate change research is largely focused on models to predict how environmental conditions will differ in the future, observations from the recent past should be analyzed closely to uncover patterns among temperature, precipitation, and yield. Presented are yield and climate data associated with five American agricultural commodities: corn (Zea mays L.), cotton (Gossypium hirsutum L.), rice (Oryza sativa L.), soybean (Glycine max), and winter wheat (Triticum aestivum). Yield data from 2000-2016, departures from usual maximum and minimum temperatures, and drought data are assessed for each crop during its growing season for the top-producing state in the United States. Juxtaposed to temperature and drought data from 2000-2016 are maximum and minimum temperatures from a base period of 1980-1999 to display the degree of change since the new millennium. A correlational analysis between crop yield and Palmer Drought Severity Index (PDSI) was performed for the 2000-2016 timeframe. Of the five crops examined, corn and cotton were statistically significant at the 5% confidence level, indicating a relationship exists between yield and PDSI. In addition to analyses presented, a literature search was conducted to discover other studies on the impacts of climatic factors on these five agricultural commodities and large-scale climate systems.